Film winding mechanism



March 14, 1939.- J B NELSON 2,150,696

FILM WINDING MECHANISM Filed Ang. 18, 1937 kwal@ wlmi?,

22 2o /8 da/7 9. /Ve/Sof? I NVEN TOR M M @mgm BY ATTOIWEYS APatented Mar.v14, 1939 y I l UNlTED STATES PATENToFFlcE FHM WINDING MEcnANlsM Jolm Nelson, aoohester, N. Y., esslgoolto Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Y. Aoplloatlon4 August la, 1937, serial No. 159,744

A5 claims. (clim-'11i This invention relates to photography and on a film F lying across -the exposure frame. more particularly to roll film cameras. 'I'he film carries perforations'P along the edge, One object .of my invention is to provide a these perforations being adapted to engage the simple ltype of film winding and control `and teeth 5 of a sprocket 6. In the present embodiv 5 counter by which film may be wound through a ment of my invention I have made the diameter 5 camera without reference to exposure indicating ofthe sprocket such that one revolution of the numerals on backing paper. Another object of sprocket will permit one exposure area to pass my invention is to provide a simple type of autoacross the exposure frame 4. matic film winding stop which will be thrown in In this camera the supply of film may be carwhen a fresh area of illm is wound into place and ried by a spool or a 'retort 1 and the im is Wound 10 which may be manually released whenthe area from this supply reel to a take-up reel 6 past the of lm has been exposed. Another object of my exposure aperture 4. invention is to provide a. device in which film In order -to wind film upon the take-up spool may be wound from a supply spool to a take-up 8, there is `a winding knob 9 shown in Fig, 5

Aspoolfor exposing the film and then may be attached to a shaft I0, passing through the cam- 15 wound back onto the original spool before removera casing I I, to rotate a spool or hub I2, including it from the camera and to provide a' strucing a slot I3 to which the end of the film F may ture which will permit this rewinding without atbe attached in threading the camera. Thus, tention from an operator. Another object of when the winding knob 9 is turned, fllin is wound my invention is to provide a film counter which to the take-up chamber. After all of the ex- *w20 works in conjunction -with the film winding posures have been made, the film may be wound mechanism, so that the number of exposures back into the original retort or onto the original which have been made can be readily determined spool 1 by means of a similar windingknob I4 from the outside of the camera. Still other obon the opposite end of the camera, this knob jects will appear from the followingspecification, being connected to a shaft I5 which is attached 25 the novel features being particularly pointed out to the spool in any known manner.

in the claims at the end thereof. Where motion picture lm is used in 'cameras Coming now to the drawing wherein like referof this type, it is customary to omit the film ence characters denote like parts throughout: backing paper, and consequently, it is necessary Fig.. 1 is a perspective view of parts, shown to omit the usual red window in the camera back. 30 schematically in broken lines, of a cameramcon- In order to measure off the exposed sections of -structed in accordance with a preferred form of film, the following mechanism is employed. Re-

' .my irl'VeIlOnferring to Fig. 5, the hub I2 carries a ratchet I1 Fig. 2 is a top plan view of the camera shown vwhich turnswith the hub and which lies in the in Fig. 1, the objective carrier being broken away. path of a pawl I6 which is pivoted upon a shaft 35 Fig. 3 is an enlarged detail section, parts being I9. This shaft, as best shown in Fig. 6, carries shown in elevation, `of the lm measuring and one or more flat portions 20, so that the pawl may locking mechanism used in the camera shown in rest against one or more shoulders 2|, being held the preceding gures. in place by means of a pin 22. The pawl I8 in- 40 Fig. 4 is a. view similar to Fig. 3 but with the cludes a-hook-like member .23 on the end adapted 40 DBMS in a Wlrlding position. to engage the ratchet I'I whenever the pawl moves Fig. 5 is a detail section showing a plan View of in the direction shown by the arrow in Fig. 4. the film winding, latching and measuring mecha- This movement is accomplished in the following nism. manner: Fig. 6 is lan enlarged fragmentary view of the As the film is wound from one roll to the other, 45 Winding 1atChre1eaS= it passes over a sprocket wheel 6 having teeth 5,

As a preferred form of my invention, I have,V this sprocket being carried by a shaft 24. The shown a camera. of the so-called miniature type shaft 24 supports a toothed disk 25 which carries adapted to take pictures on perforated motion a pin 26.

picture film. Fig. 4 shows the parts in position for film to 50 As indicated in Fig. 1, the camera may consist be wound upon the hub member I2. If the of a camera body I having an extending front winding key 9 is turned to wind lm on the hub, tube 2 which carries the 'camera objective 3.' the film, by running over the sprocket 6, will Light passing through the objective and passing turn the sprocket through the teeth 5. As the through an exposure frame 4 makes an image sprocket is moved, -the pin 26 is likewise moved, 55

passing through the position shown in Fig. 4 and continuing around until it strikes the slanting edge 21 of the pawl arm 28., Thus, the pin striking this arm of the pawl, throws the hook 28 into engagement with the ratchet I1, as indicated in Pig. 3, andv locks the winding key 8 against further movement.

In order to release this latch after the film has been exposed, there is a push-button |28, as indicated in Fig. 6, which is spring-pressed outwardly by a spring 28 through the Fcamera wall 88. This push-button is on the end of shaft I8 above described, on which the pawl I8 is pivthen take place.

Vals

llg.2thescaleand Afterallofthefilmareashavebeenexposed and it is desirable to wind the film back again into the retort 1, it is only necessary to turn the winding knob I4 to cause a reverse movement of the illm. This movement will not be interrupted at any time by the pawl and ratchet for the following reason. Each timethe pin 28 moves toward the pawl I8-when moving in the direc-4 tion shown by the arrow in Fig. 4--it will pass under the upwardly beveled edge 8l of the pawl, causing a slight compression of spring 28 and permitting the pawl to rock idly over the end of the pin as it passes beneath the ratchet. Thus, continued winding on the winding handle Il will wind the film back into the retort 1 while the pawl oscillates above the ratchet without ever being brought into engagement with the ratchet.

It is necessary to measure film and to indicate on the outside of the camera the number of exposures which have been made. To accomplish this, I have provided teeth 8l on the disk 25, these teeth meshing with a second gear 88. 'Ihe teeth 81 of this gear can be made-approximately the same in number as the teeth ot gear Il, but preferably there is either one tooth more or one tooth less on the gear 88. A greater difference may be provided if desirable, the reason for this dilerence being that for each revolution of the gear 88, the gear 88 should move a distance either greater or less than one complete revolution, so

`.pointer Ilv on ,the camera. It is obvious that Seither thescaleortheipolntermaybeattachedto tlirnwiththegear88.butwhicheverpartis moimtedtomovathetwow'illwoperatetoindicatethenumberofexposuresmade. Thus, in pointer indicate that ten -expocurhaveheenmadel 'Ihe 4structure above described is relatively simple and forms apoaitive'latch for windingthe film. in which undue strain is not placed upon theilhnbutthewindingspoolisdennitelylatched whena'predetennined amolmtofiilm hasbeen measured'oih` The mcaai'rringdevi as conltnictedinthepreferred-tilluetrated, forms a part of the latching mechanism since it forms a carrier for the pin 28 and since both of these gears are mounted to cooperate with the film winding mechanism, that is, gear 35 is fixedly carried by shaft 24 and gear 88 is freely rotatable about the axis of the winding hub I2.

The operation of this winding control is extremely simple. After having threaded the camera by stretching the film from the supply retort to the take-up spool and placing the apertures P of the film on the teeth 5 of the sprocket, it is only necessary to set the dial 48 until the zero mark appears opposite the pointer. This can be accomplished because any suitable form of friction connection can be used to attach the dial to the stub shaft 38. By winding the key 9, the film will be permitted to move until the pin 26 strikes the beveled surface 21 of the pawl I8, rocking it about its pivot I8 until the ratchet is engaged by the hook 28 of the pawl. 'I'his prevents further movement of the winding key 9 until the push-button |28 is released. After making an exposure, the operator depresses the push-button `|28 so that the shaft I8 moves axially, displacing the pawl I8 and permitting spring 3| to move the pawl over the end of the pin 28 which will be in the position shown inFlg. 3. When the pawl has been moved by depressing the push-button |28, it will lie in the position shown in Fig. 4. By turning the winding key 9, the pin will move from the Fig. 3 to the Fig. ,4;position and continue its movement until it again moves the pawl I8 against the pressure of spring 3i locking the film. These operations may be continued until all of the film has been used and it is desired to return the illm into its original container.

. To do this the windir hanne it is turned so that the nlm will move in a reverse direction. This causes the gearv 85, `and the pin 2i to move in the direction showniby the arrow in Fig. 4, from which figure it be seen'that each time the pin approaches the pawl I8, it will ride under the upwardly beveled surface 38. This will .merely cause the pawl to move axially on its shaft I8 and the hook 28 will remain out of engagement with the ratchet I1. By continuing to turn the handle Il, the film may be completely rewound.

What I claim as new and desire to secure by Letters Patent of the United States is:

1t In an automatic stop for perforated roll film cameras, the combination with supply and take up rolls, a sprocket over which the iilm passes, a ratchet on the take up roll, a pawl pivoted adjacent said ratchet, a spring tending to raise the pawl from the ratchet, and a pin carried by the sprocketadaptedto positively thrust the pawl into engagement with the ratchet, and means for manually moving the pawl to render the pin on the sprocket inoperative.

2. In an automatic stop for perforated roll nlm cameras, the combination .with supply and take up rolls, a sprocket over which the nlm passes, a ratchet on the takeup roll, a pawl pivoted adljacent said ratchet, a spring tending to raise the pawl from the ratchet. a disk carried by the sprocket. a pin proiecting therefrom and adapted to engage and -i'orce the pawl into the ratchet, a push buttonparallel to said pin for releasing the pawl therefrom whereby said spring may raise the pawl from the ratchet. Y

3. In an automatic stop for perforated roll film camerasthe combination with supply and take uprolls,asprocketoverwhichtheiiimpasses,a

,ratchet on the take up roll, a pawl pivotedadpawl to slip sprocket pin. means for re jacent said ratchet, a pivotal support for the pawl comprising an axially movable shaft, a spring tending to hold the shaft in an operative position, a second spring adapted to raise the pawl from the ratchet, a pin carried by the sprocket for positively engaging the pawl and ratchet, and means for releasing the pawl and ratchet ,manually by moving the pawl shaft axially whereby said second spring may cause the on the end of the sprocket pin.

4. In an automatic stop for perforated roll film cameras, the combination with supply and take up rolls, a sprocket over which the film passes, a ratchet on the take-up roll, a pawl pivoted adjacent said pawl comprising an axially movable shaft; a spring tending. to hold the shaft in an operative position, a second spring adapted to raise the pawl from the ratchet, a pin carried by the sprocket for positively engaging the pawl and ratchet, and means for releasing the pawl and ratchet manually by moving the pawl shaft axially whereby said second spring may cause the pawl to slip oif the end of the sprocket pin, a beveled ear on the pawl lying in the pathof the nding the film onto ratchet, a pivotal support for the the supply roll whereby said pawl may remain inoperative oscillating idly upon its pivot as the sprocket pin turns with the sprocket in a rewin'ding direction.

5. Inv an automatic stop for perforated roll film cameras, the combination with supply and take up rolls, a sprocket over which the film passeaa ratchet on the take up roll,a pawl pivoted adjacent said ratchet, a slidable pivot vfor the pawl, spring tension tending to move the pawl in two directions, in one direction away from the ratchet and inthe other direction toward an operating pin, said operating pin being mounted to turn with said sprocket, the pawl including inciined surfaces and the pin being mounted for movement with the sprocket into engagement with one inclined surface so that said pin may definitely thrust the pawl and ratchet together when moving in a winding direction and so that said pin may idle behind the pawl passing under the` other inclined ysurface when said pin is moving in a rewinrling direction whereby iilm may bev wound forward only intermittently and may be rewound without intermption.

JOHN B. NELSON. 

